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Full text of "Flora Indica Vol-I"

168                                     FLORA INDICA.                [Menispermacea.
M'enisjp&rjnacees constitute a very natural Order. The scandent habit, alternate, ex-
stipulate, palminerved leaves, petioles dilated and jointed at the base, minute, uni-
sexual, thalamifloTous flowers, arranged in a ternary order, in at least three and usually
four rows, and imbricated in aestivation, the small scale-like petals, definite stamens,
definite apocarpous ovaries, solitary amphitropal ovules and fleshy drupes, charac-
terize all the typical species, and form a combination of characters which is to be
met with nowhere else. Of these the alternate exstipulate leaves, petioles not
sheathing at the base, minute thalamiflorous.flowers, solitary ovules, and peculiar dru-
paceous fruit, are constant, but all the others are subject to exception
The scandent habit is almost universal in the Order, but it is absent in Cocculus
laurifolius, which is a small, erect (or somewhat sarmentose) tree.
The peculiar structure of the petiole so common in Menispermacea can only be
compared to that of a few Euphorbiaeea. The petiole is generally elongated and
cylindrical* without any marked groove in front, and has the appearance of being
articulated with the stem, but the leaves are seldom very deciduous. The joint is
sometimes a little above the base, so that a small projection is left on the branch
after the leaf falls away. Above the base, and sometimes also near the leaf, the
petiole is generally thickened, but contracts suddenly. The thickened portion of the
petiole is often weaker in texture than the remainder, and exhibits a tendency to
that twisting which is" characteristic of the petioles of Clematideai. In most spe-
cies of Coccul-as the petiole is short, hot dilated at either extremity, and scarcely
articulated.
The leaves of Mcnisperwacea vary much in shape and texture. The most com-
mon shape is broad cordate, or nearly round ; they arc, often peltate, but this mode
of attachment to the petiole is frequently present and abseut in the same species,
and occurs at times in young individuals, even when absent in the adult plant.
Many, however, have elongated leaves. The palmate arrangement of the nerves is
not confined to the peltate and broad cordate-leaved species, those with elongated
leaves being always three-nerved at the base. The leaves often present a great va-
riety of form, size, and texture in the same individual, so that copious suites of spe-
cimens are necessary for the proper illustration of each species.
The flowers are almost always unisexual, but Mr. Miers mentions the occurrence
of hermaphrodite flowers in Tiliacnra and Qdontocarya* lu the female flower im-
perfect stamens are usually present, and in the male more or less distinct traces of
the gynuscium are usually found, except in the tribe CissampeJidea, and other mona-
delphous genera, in which the staminal column occupies the centre of the flowpr.
The ternary arrangement of the parts of the perianth is of very general occurrence.
The most remarkable exception is met with in Mr. Miera's genus Odontocarya, in
which he describes the calyx and corolla as forming each a single verticil of five leaves.
Qdontocarya appears, however, from Mr. Miers' analysis, to be a genuine Menisper-
maeeous plant, the embryo having the laterally divaricating cotyledons of the tribe
Tinosporert* In a part of the CissampeKdtw the segments of the perianth are ar-
ranged in a binary (or more rarely quaternary) order, and in the same tribe they are
not unfrequently combined into a gamopetalous calyx and corolla. The solitary sepal
of CUsanipelos. (usually called petal) in the axil of the bract is evidently formed of
two combined sepals.
The number of verticils of the perianth is normally four, and tUcy are usually
sufficiently distinguishable into calyx and corolla, the latter being much the smallest,
BO that the petals were often described by the older botanists as nectaries or scales.
Occasionally the petals are reduced to a single verticil of three, or entirely sup-
pressed ; sometimes also the sepals are increased by the addition of one or more
verticils, or of a number of irregularly imbricated bracts. In Cotcintym the petals
arc larger than the sepals.
The imbricated aestivation of the perianth is not without exception, as in filittcora
and several Ģimaei*o the iimir sepals are vulvate. This has'been pointed out in
Tih'acor* by Mr. Miers, and iu Umetcla by Dr. Asa Gray. The petuls of Cosdnium
are in like mnanrr very slightly imbricated.